1. Field of the Invention
The present invention relates to a liquid crystal display device, and particularly to a liquid crystal display device having a screen configuration at high definition in which pixels are in a delta arrangement.
2. Description of the Related Art
Liquid crystal display devices include a TFT substrate, a counter substrate, and liquid crystals. In this case, the TFT substrate has pixel electrodes, thin film transistors (TFT), etc. formed in a matrix. The counter substrate is disposed in facing relation to the TFT substrate and has color filters, etc. formed at positions corresponding to the pixel electrodes of the TFT substrate. The liquid crystals put between the TFT substrate and the counter substrate. Images are formed by controlling the light transmittance of liquid crystal molecules of each pixel.
Since the liquid crystal display devices are flat and light in weight, their application use has been extended in various fields, for example, from large-sized display devices such as television sets to mobile phones and DSCs (Digital Still Cameras). Particularly, in DSC, etc., high screen definition is required. As the screen definition is higher, the size of the pixel is reduced. A TFT and a pixel electrode are present in each pixel and when the size of the pixel is reduced, the size of the pixel electrode is decreased relatively. Accordingly, transmittance of light from a backlight in the screen is lowered to decrease the luminance on the screen.
On the other hand, a red filter (R), a green filter (G), and a blue filter (B) are present in a counter substrate to enable color display. A black matrix is filled between each of the filters. The black matrix serves to prevent interference between each of colors, and improve the screen contrast by using a black color for a portion not concerning display. The black matrix also serves to prevent external light from impinging on the TFT in a portion where the TFT is formed, thereby preventing a light current from flowing to the TFT. As the area of the black matrix is larger, the amount of the transmission light from the backlight decreases to lower the luminance on the screen.
JP-A-2009-36795 describes that the area for the black matrix is decreased and the luminance on the screen is improved in a usual pixel arrangement by changing the order of disposing filters in the lateral direction for a specified color thereby disposing a filter having identical color between pixels adjacent to each other in the lateral direction and forming a region where a black matrix is not present. In this case, the usual pixel arrangement is a pixel arrangement in which filters having identical color are disposed in the longitudinal direction while different filters, for example, a red (R) filter, a green (G) filter, and a blue filter (B) are disposed in the lateral direction.